Compared with other welding technologies, the main advantages of laser welding are:

1. Fast speed, large depth and small deformation.

2. It can be welded at room temperature or under special conditions, and the welding equipment is simple. For example, when a laser passes through an electromagnetic field, the beam will not be deflected; the laser can be welded in vacuum, air, and a certain gas environment, and can be welded through glass or materials that are transparent to the beam.

3. It can weld refractory materials such as titanium, quartz, etc., and can weld different materials with good effect.

4. After the laser is focused, the power density is high. When welding high-power devices, the aspect ratio can reach 5:1, and the maximum can reach 10:1.

5. Micro welding can be carried out. After the laser beam is focused, a small spot can be obtained, and it can be accurately positioned, which can be applied to the group welding of micro and small workpieces in mass automatic production.

6. It can weld hard-to-reach parts, and implement non-contact long-distance welding, which has great flexibility. Especially in recent years, optical fiber transmission technology has been adopted in YAG laser processing technology, so that laser welding technology has been widely promoted and applied.

7. The laser beam is easy to realize the beam splitting according to time and space, and can carry out multi-beam simultaneous processing and multi-station processing, which provides conditions for more precise welding.

However, laser welding also has certain limitations:

1. The welding parts are required to be assembled with high precision, and the position of the beam on the workpiece cannot be significantly shifted. This is because the spot size is small after the laser is focused, and the welding seam is narrow, which is filled with metal materials. If the workpiece assembly accuracy or beam positioning accuracy does not meet the requirements, it is easy to cause welding defects.

2. The cost of lasers and related systems is high, and the one-time investment is large.

Laser welding heat conduction

Laser welding is to irradiate a high-intensity laser beam to the metal surface, and through the interaction between the laser and the metal, the metal is melted to form a weld. Metal melting is only one of the physical phenomena during the interaction of the laser with the metal. Sometimes light energy is not mainly converted into metal melting, but manifested in other forms, such as vaporization, plasma formation, etc. However, to achieve good fusion welding, metal melting must be the dominant form of energy conversion. To this end, it is necessary to understand the various physical phenomena generated in the interaction between laser and metal and the relationship between these physical phenomena and laser parameters, so that most of the laser energy can be converted into metal melting energy by controlling the laser parameters to achieve welding. Purpose.

1


Post time: Jan-12-2022